The US military cannot locate hundreds of sensitive nuclear missile components, according to several government officials familiar with a Pentagon report on nuclear safeguards.

Robert Gates, US defence secretary, recently fired both the US Air Force chief of staff and air force secretary after an investigation blamed the air force for the inadvertent shipment of nuclear missile nose cones to Taiwan.

According to previously undisclosed details obtained by the FT, the investigation also concluded that the air force could not account for many sensitive components previously included in its nuclear inventory.

One official said the number of missing components was more than 1,000.

The disclosure is the latest embarrassing episode for the air force, which last year had to explain how a bomber mistakenly carried six nuclear missiles across the US. The incidents have raised concerns about US nuclear safeguards as Washington presses other countries to bolster counter-proliferation measures.